scswift:
http://datasheets.maximintegrated.com/en/ds/MAX9744.pdfThen there's another snag On page 8 of the amplifier's datasheet there's a graph for 12V into 4ohms, where it shows efficiency (%) & power dissipation (mW) vs output power, which doesn't make any sense. If the amplifier is 85% efficient at 16W output, how is it the power dissipation is only 5mW?
Two things - there's a misprint in the datasheet (a common occurence!) and it should be
W, not mW for the dissipation. Secondly its a stereo amplifier so you have twice the
dissipation, so 90% efficiency at 20W means 4W dissipated.
Also remember most audio signals are nowhere near maximum amplitude most of
the time, its only the percussive peaks that get up there, so in practice the dissipation
will be a lot less than the maximum.